Computed Tomography and Magnetic Resonance Imaging are Similarly Reliable in the Assessment of Glenohumeral Arthritis and Glenoid Version.

Abstract

The purpose of this study was to compare the intraobserver and interobserver reliability of CT and T2-weighted MRI for evaluation of the severity of glenoid wear, glenohumeral subluxation, and glenoid version. Sixty-one shoulders with primary osteoarthritis had CT and MRI scans before shoulder arthroplasty. All slices were blinded and randomized before evaluation. Two fellowship-trained shoulder surgeons and three orthopaedic surgery trainees reviewed the images to classify glenoid wear (Walch and Mayo classifications) and glenohumeral subluxation (Mayo classification). Glenoid version was measured using Friedman's technique. After a minimum two-week interval, the process was repeated. Intraobserver reliability was good for the CT group and fair-to-good for the MRI group for the Walch, Mayo glenoid, and Mayo subluxation classifications; interobserver reliability was poor for the CT and fair-to-poor for the MRI group. For the measurement of glenoid version, intraobserver reliability was good for the CT and substantial for the MRI group; interobserver agreement was good for both groups. There were no significant differences in reliability between staff surgeons and trainees for any of the classifications or measurements. CT and MRI appear similarly reliable for the classification of glenohumeral wear patterns. For the measurement of glenoid version, MRI was slightly more reliable than CT within observers. Differences in training level did not produce substantial differences in agreement, suggesting these systems can be applied by observers of different experience levels with similar reliability.